820765 has 8 divisors (see below), whose sum is σ = 1074528. Its totient is φ = 596880.

The previous prime is 820763. The next prime is 820789. The reversal of 820765 is 567028.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 820765 - 2¹ = 820763 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820763) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7407 + ... + 7516.

It is an arithmetic number, because the mean of its divisors is an integer number (134316).

2⁸²⁰⁷⁶⁵ is an apocalyptic number.

It is an amenable number.

820765 is a deficient number, since it is larger than the sum of its proper divisors (253763).

820765 is a wasteful number, since it uses less digits than its factorization.

820765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14939.

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 820765 is about 905.9608159297. The cubic root of 820765 is about 93.6281141957.

The spelling of 820765 in words is "eight hundred twenty thousand, seven hundred sixty-five".